CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN PARTNERS' CAPITAL (Unaudited) - USD ($) $ in Millions	Total	Accumulated Other Comprehensive (Loss) Income	Partners' Capital
Beginning balance at Dec. 31, 2020	$ 5,249.1	$ (79.8)	$ 5,328.9
Add (deduct):
Net income	184.3		184.3
Other comprehensive income, net of tax	1.1	1.1
Ending balance at Jun. 30, 2021	5,434.5	(78.7)	5,513.2
Beginning balance at Mar. 31, 2021	5,367.1	(79.3)	5,446.4
Add (deduct):
Net income	66.8		66.8
Other comprehensive income, net of tax	0.6	0.6
Ending balance at Jun. 30, 2021	5,434.5	(78.7)	5,513.2
Beginning balance at Dec. 31, 2021	5,469.1	(72.6)	5,541.7
Add (deduct):
Net income	180.0		180.0
Other comprehensive income, net of tax	1.1	1.1
Ending balance at Jun. 30, 2022	5,650.2	(71.5)	5,721.7
Beginning balance at Mar. 31, 2022	5,594.8	(72.1)	5,666.9
Add (deduct):
Net income	54.8		54.8
Other comprehensive income, net of tax	0.6	0.6
Ending balance at Jun. 30, 2022	$ 5,650.2	$ (71.5)	$ 5,721.7